This reminds me of one of the first times I traveled overseas with my spouse, and they brought a hairdryer. I noticed they'd packed it before we left, and I told them they wouldn't need it. They kept insisting on bringing it, though, despite my protests the hotel would surely have one. I tried to sneak it out of their suitcase, but they'd sneak it back in.
Finally, while I'm relaxing in our hotel room in Rome and they're in the restroom, I notice the lights and TV dim and flicker. A few seconds later, they emerge from the bathroom, rummage through some luggage, then head back to the bathroom. Lights dim and flicker again. They emerge again, rummage through the luggage some more, go back to the bathroom... lights dim and flicker again. Finally I figure I need to find out what's going on. I get up, walk over to the bathroom door, and knock. They open, and with their hairdryer in one hand and pointing to our travel adaptors with the other, exasperatingly complain, "None of these travel adaptors work!". You guessed it! They blew the fuse in every single one.
Moral of the story? If anyone needs the location of a good electrician's shop within short walking distance of the Piazza di Spagna where you can buy fuses, I know a guy!